New England Patriots tight end Rob Gronkowski (87) is taken off the field in the second half of a game against the Cleveland Browns at Gillette Stadium. / David Butler II, USA TODAY Sports

by Peter Barzilai and Erik Brady, USA TODAY Sports

by Peter Barzilai and Erik Brady, USA TODAY Sports

NEW YORK - NFL players worry about head injuries and their potential long-term consequences but not nearly as much as they worry about injuries to their legs, particularly their knees, that can end careers.

USA TODAY Sports surveyed 293 players on 20 NFL teams and asked what body part they were most concerned about injuring in a game: 46% said knees or other parts of their legs, 24% said head and neck and 26% said none.

The poll of players on active rosters was conducted from mid-December to early January and has a margin of error of plus or minus 5 percentage points. If requested, players were granted anonymity because they were concerned about fallout to their vote going public.

The results seem surprising given all of the emphasis the NFL and the culture at large have given to the life-altering dangers of concussions in recent years.

"Anytime you can avoid hits to the head it's great," Chicago Bears running back Michael Bush said, "but if you get hit in your knees, that's your career."

New York Jets defensive tackle Leger Douzable is another example of the here-and-now thinking of many players. He is more aware of head injuries but more fearful of a serious leg injury.

"For me, it's the knee," he said. "That's the one that gets me, not the head or anything. A head injury? Don't get me wrong, that's bad. No one wants a concussion. But, here and now, a knee injury can be career-ending."

The USA TODAY Sports survey also asked players whether NFL rule changes on hits to the head had made the game safer. Thirty-nine percent said they had, but a majority - 53% - said safety was about the same and 8% said the game was less safe.

"You can't make a vicious game safe at the end of the day," said Seattle Seahawks cornerback Walter Thurmond, whose team will meet the Denver Broncos on Sunday in the Super Bowl. "The nature of the game is violence, and it's been about that since its creation."

To many players, they are in a no-win situation - more rules to avoid hits to the head are causing more hits to the knees.

Several players pointed to the December play on which New England Patriots tight end Rob Gronkowski took a knee-to-helmet hit when Cleveland Browns safety T.J. Ward came in low. Gronkowski tore his right anterior cruciate and medial collateral ligaments in the violent collision.

"You saw what happened to Gronkowski," Browns guard Shawn Lauvao said. "That's because of a rule change. The way it was before, he would have just got hit in the head. He would have been there for the next play. It's a Catch-22. I know they're trying to make it safer, but some rules changes just take away" from the game.

Do the rule changes take away from the quality of play? More than half (53%) of the players surveyed said they thought the quality of NFL games remained essentially the same after the rule changes while 18% said games were better and 29% said they were worse.

Baltimore Ravens defensive end Chris Canty said the game had improved. "It's the greatest game in the world, (and) viewership and the game's popularity would support that," he said.

New Orleans Saints safety Kenny Vaccaro said it was worse. "Fans come to see us bang, see us hit. Now it's almost like flag football. I think it has changed the integrity of the game," he said.

Green Bay Packers offensive tackle Bryan Bulaga said it was the same. "I still think the game is great. I really do," he said. "I think the game is being played physical. I don't think it's backed down at all. There's a lot of good collisions happening. You see it every Sunday, clean hits, good hits.

"So I don't think it's done anything to the game. I just think the NFL has taken steps to really hammer the player safety home. And I think all the guys appreciate that, and everybody wants to be looked after by the league."

Except some players, mostly defensive ones, think the league is better at looking after some players than others.

"What about linemen diving at knees? What about chop blocks? It's like, 'Quarterbacks are the face of the league, and we're not disposable. But you linemen are. We can get more of you. We can only get one or two Tom Bradys.'"

As Washington Redskins cornerback DeAngelo Hall put it: "The game is safer for certain players: quarterbacks, receivers, I guess punters now. The rest of us still get the crap beat out of us."

Jeff Miller, NFL senior vice president of health and safety policy, said, "We take those comments very seriously." He said the NFL's competition committee would examine the data to see whether those concerns were well placed and whether changes needed to be made.

Short-term view

Kevin Guskiewicz is research director of the Center for the Study of Retired Athletes, among his many titles at the University of North Carolina, where he studies concussions and interviews hundreds of former pro and college players.

"These guys who are 50 and 60 years old tell me that when they were playing they were only concerned about next week, not 10 or 20 or 30 years down the road," he said. "They were always thinking about the next game."

That's why Guskiewicz says he is not at all surprised to hear today's players worry more about their knees than their heads. He thinks that's a reflection of age and ambition more than a disregard for concussions.

"Players know that knee injuries can be season-ending or even career-ending," he said. "We're talking about their livelihoods. I don't think they perceive concussions as season-ending or career-ending."

Guskiewicz, who is chairman of an NFL subcommittee on safety equipment and rule changes, says players are much more tuned in to the dangers of concussions today than they were even a few years ago.

"I'll bet if you asked that question about which body part 10 years ago, it would have been under 10% who said they worried about their heads," Guskiewicz said. "I think we are making progress, but it still speaks to being ready next week or next season and not being quite ready to think about what they'll be like at 45 or 55."

Aman Alexander, chief executive officer of Sunstone Analytics, which provides medical and performance analytics to professional sports teams, agrees with players who note knee injuries are far more damaging to their earning potential than concussions. "It's clear from analysis of NFL and NCAA injuries that players realize what injuries are likely to impact their ability to get drafted and perform," Alexander said. "Meniscal and cartilage procedures and ACL reconstructions are statistically the most damaging injuries, especially at running back and offensive line positions, while concussions - even multiple concussions - have no statistical impact on the odds of getting drafted or performance."

Rise in ACL injuries?

Cardinals receiver Larry Fitzgerald is among those who say tacklers aiming lower means more leg injuries.

"There's less head trauma issues this year, with the emphasis on helmet-to-helmet contact," he said. "But there's been a lot of catastrophic injuries to lower extremities, like Dustin Keller, Rob Gronkowski, Randall Cobb. Hurt is hurt."

According to the American College of Sports Medicine, NFL teams reported an average of 43 total ACL injuries a season from 2002 to '12. Sunstone Analytics research says there have been 65 ACL injuries in the 2013 season, though that includes injuries suffered in spring practices, training camp and the preseason.

The NFL's Miller said the league would study the data on injuries after the season. He cautioned against drawing conclusions not fully informed by the annual data.

"When we look at the number of injuries and the types of injuries and the breakdown as to when and where and how those injuries occur, that's going to inform the decision-making in terms of the health and safety measures that we take," he said. "So if it turns out that the concern that is expressed in your survey is well-founded as we look at the number at the end of the year, then that's something we're going to have to address."

Miller said the league would look into player concerns expressed in the survey.

"We share the concern about all player health and safety issues," he said. "Wherever the injuries occur, we need to look at those and move on and make the game safer where we can. The culture change at least around head injuries is going to take some time."

Patriots running back Shane Vereen says the game is safer but can never really be safe.

"I think what you have to keep in mind is that it's a physical game," he said. "You're going to get concussions regardless. You're going to get shoulder injuries regardless of how good your shoulder pads are. It's a physical game. We know coming in."

Still, he thinks the new rules are good for the game and for the players.

"I think it's safer as far as the concussions and the targeting of the head," Vereen said. "I think that's very important. Especially later down the line, where we're seeing examples of where that can go bad. I think they've done a good job as far as keeping players' head safe."

Saints guard Jahri Evans believes that players must look out for each other. "I don't want to go for somebody's knees and risk getting him hurt just because he's the guy across from me," he said. "I hope he feels the same way about me."

Evans said he understands why defensive backs go low "on a 280-pound tight end like Gronkowski because that's the best way (the DB) knows to get him down. But as career professionals we've got to do a better job of looking out for our fellow pros. We need to do a better job of policing ourselves and protecting each other."

Saints fullback Jed Collins is among the players who take the long view and worry more about concussions than other injuries.

"A bum shoulder or a blown-out knee is one thing," he said, "but my brain is the thing that makes me who I am."

Ravens tight end Dallas Clark seconded that. "There's no known fix for the damage of concussions, the hits to the brain," he said. "That's a no-brainer."